I don't see the big deal. Are you against the whole story of the Divide or this information about it coming from Navarro?
I just don't think it was necessary or see why they chose Navarrro as the source of this device. I can only think of it as some tangently ED-E related link which isn't really supported by logic. It's not a big deal, all I am saying that instead of having us all question whether the NCR took decades to realise what they had and this and that; we now have a scenario where the imperialist NCR trust a single courier, who's only affiliation with the NCR was that he was born in what they called their land, with something that leads it back to a Nuclear Missile Silo.
"They do, however, recognize the symbols (American flag,
silo stencils, etc.) and recognize it might be tied to the same symbols and markings the NCR found at the Divide."
Someone at the NCR recognised that this had markings specific only to a pre-war ICBM Silo, also consider that the only way that the Silo Stencils could have been recognised is that if some NCR personnel went back to the OSI in Shady Sands or where-ever and recognised them or that the NCR - which would suggest maybe researchers where already at Hopeville - or that someone in the NCR recognised them from reports and files - either way indicating that the NCR was looking into these Silos and knew what they were. So the NCR knew that this device was related to a find of pre-war ICBM and tasked a lone, potentially un-affiliated or sympathetic Courier with this?